First of all, you need to know that I'm a total beginner so please know this before using acronyms.

I am extremely interested in Guild Wars 2 and am eagerly awaiting its release. In an attempt to unlock all the loyalty HOM weapon and pet rewards and occupy myself waiting for the release date, I purchased Guild Wars: Complete Collection. It should be coming in next week from the UK.

Can you guys recommend some builds and character types to solo (mainly) successfully to unlock at least to 30/50?

For the most part, anything goes in normal gameplay. Pretty much just find a build type you enjoy, and run with it. I used the same build with very little variation across all 3 campaigns, as well as the expansion.

For characters I know things about:
I find mesmer and assassin to be not great for general soloing with hero/hench group. Great for specialized high end groups though.
Monk was a royal pain in terms of controlling AI, so I gave up on it... but maybe it was just me.
Otherwise pretty much anything goes.
Earth ele probably most leveled (in terms of difficulty) across all types of enemies in hard mode. Warrior (I run Rage of Ntouka with sword build) is easiest and most fun unless going against many non-fleshy creatures, especially ice elementals, then its a royal pain.
Paragon a notch less manly than warrior, but still moderately fun and more room for mistakes with "Save Yourselves!" on your bar.
Necro and Ritualist are easy (unless going against mesmer/monk heavy mobs) but boring.
But really anything goes. There are plenty of builds for every class on pvx wiki to pwn faces with.

With a very basic build, I think monk is the best. WoH or divine boon/prot monk are pretty good. Just make your monk hero the opposite of you and you should be able to keep everyone up pretty easily. Also, unless it's important to a hero's build, make their secondary profession monk or rit so they can res repeatedly.

And as it has been said, if you can get the skills, spirit spam rit turns pve into easy mode.

Bluntly put, it really doesn't matter as its more how you use the skills then the class themselves. If you really want the help, you can do one of 2 things. Either try to join a guild and ask a member or save up some gold (a few thousand) and have someone run you to Istan (part of the Nightfall campaign). If your not in Nightfall this will cost more gold then being in Nightfall. When your in Istan you can get yourself some Heros (http://wiki.guildwars.com/wiki/Hero). Heros are AI controlled players that you can customize, from weapons and armor to skills equipped. Heros are different from Henchmen because you can't customize Henchmen and Heros level up with you (they start are level 15). I did that when I started play Guild Wars Prophecy, got myself my Heros and went back and started more or less soloing with them. Heros also have access to any unlocked skill you have on your account for free (so if you really want them to have different skills you can play some PvP and unlock them with Balthazar faction points.) At the moment you can only have 3 Heros in a party at one (3 per player, so if you and 1 other person join it can be you, your 3 Heros, the second player and their 3 Heros making a max party of 8). Note though that in a little while (not sure the exact date) you will be able to make a complete party of Heros though (mentioned here: http://wiki.guildwars.com/wiki/Upcom...s_and_features).